Probably have to take it apart to find the looseness since its aftermarket. The problematic bushing is in the left (longer) end; the rack-gear on the right side is normally located by a steel 'shoe' and spring with a cover plate on the short side in an OEM Cam Gears assembly. Your '73 should also have the factory bump-steer shims between the rack body and the front trunk mounting area, with longer bolts to accommodate the shims. The rebuild procedure and an exploded view is in the blue cover 'Pantera Service Highlights' manual.
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